Heat ghee in a large pot over medium heat; cook and stir onion until tender, about 5 minutes. Stir garlic, curry powder, cumin, ginger, salt, turmeric, cardamom, cinnamon, cayenne pepper, and nutmeg into onion; cook and stir until fragrant, about 1 minute.
Stir chicken into onion mixture; cook for 2 minutes. Stir carrots, coconut milk, cashews, and tomato paste into chicken mixture; simmer for 5 minutes. Stir cauliflower into chicken mixture; simmer, covered, until vegetables are tender and chicken is cooked through, about 5 minutes.
Stir peas, red bell pepper, and cream into chicken mixture; reduce heat to low, cover, and simmer until heated through, about 10 minutes.